Onshore wind policy statement: consultation paper

Statement reaffirming Scottish Government's existing onshore wind policy and seeking views on issues relating to supporting the sector.

5. Barriers To Deployment

Electricity networks

The deployment of additional onshore wind will require accompanying investment in the transmission and distribution networks. Network capacity will need to keep pace with the building of generation to allow new projects to connect in a timely and cost-effective manner and export power to where it is needed.

The application of smart technologies has the potential to allow network assets to be used more effectively and connect new generation while avoiding costly grid reinforcements. Scotland's networks have been at the forefront of innovation in the application of Active Network Management which has improved access to the distribution network and facilitated generation around network constraints. The Scottish Government supports the progression of pilot schemes into 'business as usual' operations by the network companies. We will consider the ways in which the Scottish Government can support this process.

Alongside sufficient network capacity, stability and clarity in the GB transmission and distribution networks charging arrangements is vital. This would enable developers to forecast network costs with a greater degree of certainty. The Scottish Government notes that both Ofgem and National Grid as System Operator have announced comprehensive reviews of current charging methodologies. The Scottish Government will work closely with the determining bodies to ensure that the impacts of proposed changes on the Scottish energy system are well represented within future reviews and taken account of in decision-making.

Civil aviation radar

Wind developments can impact significantly on civil air traffic control primary radar systems because they appear as clutter on radar displays, potentially obscuring aircraft flying above them from view. This is a common factor in creating delay and cost to wind power developments.

New technologies have emerged with the potential to mitigate the impacts of wind development on civil aviation radar. In particular, testing of new radar technologies at Glasgow, Edinburgh and Prestwick airports, offers the potential for barriers to wind farm development due to impacts on airport operations to be significantly eased in future.

There are numerous mitigations schemes in place which use one or more radars as 'in-fills' to mitigate impacts on another radar. However, the Scottish Government recognises that the context has now changed radically. The need to reduce the financial burden of mitigating impacts on radar has become paramount.

The Scottish Government confirms a renewed commitment to working with airports, radar operators and the wind industry in order to drive a more strategic approach to mitigating impacts of wind development on civil aviation radar. This should include establishing the potential that exists for the data from new wind farm tolerant radars to be used in a strategic way which maximises the potential for mitigation across the central belt, and the approaches which reduce the costs to developers of accessing data from 'in-fill' radar provided for the purposes of mitigation.

Military aviation radar

Wind developments can also impact significantly on military radar systems and the operations of the RAF. This is a common factor in creating delay and cost to wind developments of all scales above micro wind.

For air defence radar, various developments have benefited from existing mitigation solutions, and these may be applicable to new developments. However, the cost of securing an assessment of mitigation potential from the radar operator is prohibitive for small developments, particularly now subsidies have been removed or greatly reduced. The Scottish Government will continue to work with the radar operators and the MoD to find ways of facilitating affordable solutions to impacts on air defence radar.

With regards to military air traffic control ( ATC) radar, there is the potential for 'in-fill' solutions to provide mitigation, and there are various new technologies on the horizon which have the potential to mitigate impacts at ATC radar installations.

However, the high cost of mitigating impacts of wind development on military air traffic control radar threatens to make proposed developments uneconomic. The MoD's approach to financial risk means developers may be required to provide unworkable levels of financial security which, for many developments will be untenable.

The Scottish Government will continue to work with the MoD and developers to support a more proportionate and affordable approach to mitigating impacts on military air traffic control radar.


This policy statement makes it clear that the Scottish Government would like to see the most efficient use of Scotland's wind energy generating potential. Eskdalemuir is an area where it is proposed it would be beneficial in practice to use a strategic initiative to maximise the generating output of an area.

The Eskdalemuir 'noise budget'

The UK is bound by the Comprehensive Nuclear-Test-Ban Treaty not to compromise the detection capabilities of the Eskdalemuir Seismology Array ( EKA). Departmental responsibility for the operation, maintenance and safeguarding of the EKA rests with the Ministry of Defence (MoD).

The statutory framework and MoD's approach to the safeguarding of the EKA from the impact of wind turbines was originally established on the basis of the recommendations of the Report prepared by Keele University in 2005 (the '2005 Styles et al Report'). A limit on the cumulative impact of the seismic ground vibration produced by wind farm developments within a 50km zone centred on the EKA was set. This threshold has come to be referred to as the 'noise budget'. Additionally, within the 50 km zone, again centred on the array, an exclusion or non-development zone of 10 km was necessary.

Some time ago, the specified threshold of background seismic ground vibration from wind development was reached based on the model developed in 2005, and the MoD began objecting to further wind development. This meant that the issue became a significant barrier to the deployment of wind energy in this large area around the EKA.

Reconvened Eskdalemuir Working Group ( EWG)

In 2012, the EWG was reconvened by the Scottish Government, and a new physics-based methodology for calculating seismic ground vibration from wind development was developed. A report: 'Seismic vibration produced by wind turbines in the Eskdalemuir region. Release 2.0 of Substantial Research Project.' commissioned by the EWG was published in 2014. The report confirmed that there was in fact considerable headroom in the noise budget which would allow for further wind farm development without breaching the seismic ground vibration threshold. This has been successful in facilitating further development within the 50 km zone.

However, the research also demonstrated that the impact of seismic vibration from wind turbines on the EKA decreases rapidly with distance from the Array and that the installation of wind turbines in close proximity to the EKA would rapidly exhaust any available headroom in the noise budget. The EWG therefore concluded that it would be advisable to extend the current 10 km exclusion zone, where wind development is not permitted, outward to 15 km.

Policy consideration

Having accepted the report's findings, the EWG concluded that an extension of the non-development area around the Array represented an appropriate 'light touch' intervention that would encourage a more efficient and effective distribution of the noise budget headroom across the development zone. A 15 km radius would ensure that sufficient budget headroom would be available to bring forward the maximum level of deployment. See the map below.

The Scottish Government is minded to accept the EWG's recommendation to increase the non-development zone from 10 Km to 15 Km. We consider that this is a sensible way forward given the Report's findings and should provide fair access to the budget to maximise development across the wider consultation zone.

Map showing Eskdalemuir exclusion and consultation zones


5.1 Do you agree with the Scottish Government proposal to facilitate a strategic approach to the access to, and the cost of using, data from civil aviation radar to mitigate impacts of wind development on civil aviation operations?

5.2 Do you agree with the Scottish Government proposal that the exclusion zone round the Eskdalemuir array should be set at 15 km?


Email: Debbie Kessell

Back to top